Racing Alignment: Caster
The caster angle is the forward or backward angle of a line drawn through the upper and lower steering pivot points when viewed directly from the side of the vehicle. Caster is measured in degrees by comparing a line running through the steering system's upper and lower pivot points (typically the upper and lower ball joints of an A-arm or wishbone suspension design, or the lower ball joint and the strut tower mount of a McPherson strut design) to a line drawn perpendicular to the ground. Caster would be positive if the line slopes towards the rear of the vehicle at the top, and negative if the line slopes towards the front.
Caster angle settings allow the car to balance steering effort, high speed stability and front end cornering effectiveness. Increasing the amount of positive caster will increase steering effort and straight line tracking, as well as improve high speed stability and cornering effectiveness. Positive caster also increases tire lean when cornering (almost like having more negative camber) as the steering angle is increased.
Whiteline offers many caster improving products. Ranging from .5-2.5 degrees. Whiteline accomplishes this with offset sleeves or full offset bushings depending on the vehicle.
Head on over to the website to check out all the caster improving products Whiteline has to offer.